reading glasses 1.Material:CR-39 plastic & glass 2.Index:1.499 ... certificates reading glassesLocated in Danyang, the base of optical lens, Danyang Bosen Optical Co., Ltd is specialized in the production and ... M/C, size: 65/70/72 mm)3. BIFOCAL LENS (glasses & CR-39. round-top bifocal, flat-top bifocal, blended bifocal ... lens)4. PROGRESSIVE LENS5. POLYCARBONATE LENS6. PHOTOCHROMIC LENS reading glasses